Jolter control

ABSTRACT

A jolter control in which the outlet control element is displaceably arranged with respect to the inlet control element that is connected with the table of the jolter whereby the outlet control element is displaced by the movement of the squeezing piston.

United States Patent 1 1 1 1 3,796,133

Weiss 5] Mar. 12, 1974 JOLTER CONTROL [75] Inventor: Giinter B. Weiss, Sollinger, [56] References Cited Germany UNITED STATES PATENTS [73] Assignee: Badische Maschinenfabrik GmbH, 5 g 91/207 Karlsruhe Germany 2,619,695 12 1952 Young 91/207 [22] Filed: Aug. 3, 1971 Appl. No.: 168,701

Foreign Application Priority Data Aug. 3, 1970 Germany P 20 38 5040 vs. c1 ..I 91/207, 91/217, 91/231,

91/277 Im. 01. F011 31/00, FOlb 15/02 Field of Search 91/207, 208, 209, 277,

Primary Examiner-Paul E. Maslousky Attorney, Agent, or FirmCraig, Antonelli & Hill [57] ABSTRACT A jolter control in which the outlet control element is displaceably arranged with respect to the inlet control element that is connected with the table of the jolter whereby the outlet control element is displaced by the movement of the squeezing piston.

15 Claims, 3 Drawing Figures PATENIEU AR *2 W 3796133 SHEET 3 BF 3 I LJ 2; memo/.-

JOLTER CONTROL The present invention relates to an improvement of a jolter control for such jolters as can also vibrate under squeezing pressure.

In the casting art jolters are known for the compacting of molding sand which possess different types of controls. With the so-calledexternal control the control is mounted separate from the working piston on the outside of the machine and is directly and synchronously driven by the piston and cylinder. This control is accessible from the outside. By adjusting the control cross sections and control durations the filling of the jolter or vibrator cylinder can be matched to the load. This type of construction is expensive and involves a large number of parts and is therefore used only with large machines in order to increase the operating range thereof.

With smaller machines the so-called internal control is generally used because it. is much less expensive and more simple. However, this internal control entails the disadvantage that is sensitive against load changes since it cannot be adjusted. These machines are frequently equipped with a power press in order to compact the back of the mold after the vibration or jolting operation. In order to reach as great a density of the molding sand as possible, one also lets the jolter run during the tamping or squeezing operation. This requires heretofore a compromise as regards the favorable conditions for a free jolting and a vibration under compacting pressure insofar as the anvil weight, spring characteristics and control are concerned. By reason of this compromise the jolter is sensitive against any slight decrease in the air pressure below the prescribed air pressure as is unavoidable inoperation. In such a case the jolter no longer starts squeezing pressure. This leads to inadequately compacted molds and rejects in the production, especially in automatic installations.

A further disadvantage of the heretofore customary anvil jolters with internal control resides in that this non-adjustable control keeps constant the overall amplitude between cylinder with table, on the one hand, and vibrator or jolter piston, on the other. This has as a consequence that if the amplitude of the table becomes zero during vibration under compacting pressure, the amplitude of the anvil reaches about twice the value as during free jolting and therewith a quadruple inertia force compared to stationary machine parts occurs. Hence, the machine has to be constructed relatively heavy and expensive in order to satisfy these stress requirements. One is therefore interested to keep the amplitude of the jolter small under squeezing pressure in order to avoid excessively large stresses and loads of the machine and to benefit from a corresponding higher number of impacts per time unit.

The present invention increases the operating range of these machines without increasing the load thereof, with optimum operating conditions by influencing the anvil amplitude, in that the outlet control element is displaceably arranged at the inlet control element connected with the table. According to the present invention the adjustment of the control is provided in such a manner that the displacement of the outlet control edge takes place by the displacement of the outlet element with respect to the inlet control element by means of a regulating rod secured at the squeezing piston. The unequivocal position of the control elements with respect to each other is assured thereby in that a spring is provided between the outlet control element and the inlet control element.

Accordingly, it is an object of the present invention 'to provide a jolter control which avoids by simple means the aforementioned shortcomings and drawbacks encountered in the prior art.

Another object of the present invention resides in a jolter control for jolters permitting operation also under squeezing pressure which is relatively inexpensive and simple in construction yet is so insensitive to changes in the air pressure.

A further object of the present invention resides in a jolter control for a jolter with internal control which permits operation of the vibrating. mechanism during squeezing without danger of overloading any parts thereof.

These and further objects, features and advantages of the present invention will becomes more apparent from the following description when taken in connection with the accompanying drawing which shows, for purposes of illustration only, one embodiment in accordance with the present invention, and wherein FIG. 1 is a cross sectional view through an anvil jolter with internal control in accordance with the present invention,

FIG. 2 is a partial cross sectional view, on an enlarged scale, showing the position of the jolter control of FIG. 1 without squeezing pressure and FIG. 3 is a partial cross sectional view, on an enlarged scale, showing the position of the jolter control of FIG. 1 with squeezing pressure.

Referring now to the drawing wherein like reference numerals and used throughout the various views to designate like parts, and more particularly to FIG. 1, the machine frame designated therein by reference numeral 1 contains the squeezing and guide cylinder 2 in which is guided the guide piston 4 of the table 3. The jolter or vibrator cylinder 5 is a component of the table 3 and is supported in the rest condition by way of an abutment ring 6 on the anvil 17 and by way of the anvil spring 8 and the squeezing piston 9 at the machine frame 1. The squeezing piston 9 receives its energy supply by way of the line 10 and the jolter or vibrator piston 15 by way of the line 1 l. The compressed air is conducted to the jolter or vibrator by way of the bores 13 and 14. The jolter or vibrator piston 15 is component part of the anvil 7.

In the position of the parts illustrated in FIG. 2, the spring 16 separates the inlet control element 12 from the outlet control element 17 which is guided on an extension 18 of the inlet control'element l2 and whose end position is determined by the nut 19. The outlet control edge is designated by reference number 20. A regulating rod 21 is guided in its upper end on the extension of the outlet control element 17 and is retained at its lower end in the threaded element 22. The lower end of the regulating rod 21 is provided with an external thread and with a square end portion 23 by means of which the rod 21 can be rotated, for example, by an appropriate tool. A-sheet metal plate 24 with a square opening which acts as means for preventing rotation of the rod 21, is detachably connected with the threaded element 22. A cover 25 at the bottom of the guide cylinder 2 makes the regulating rod 21 readily accessible from below.

OPERATION The operation of the improved control in accordance with the present invention is as follows.

During jolting or vibration without squeezing pressure, the squeezing piston 9 and'the regulating rod 21 are in their lowermost position (FIG. 2). The upper end of the regulating rod 21 then has a small distance d from the outlet control element 17 which is retained in the position determined by the nut l9 by means of the spring 16. If the control now receives air under pressure by way of the line 13, then the jolter or vibrator cylinder is filled by way of the open inlet control edge 26 and line 14. As a result thereof, the table 3 is raised whereas simultaneously the anvil 7 is pressed downward. When both parts have been displaced with respect to each other by the distance a in FIG. 2, the outlet opens at 20 so that the table 3 and the anvil 7 reverse their direction of movement until the table and anvil meet at the impact ring 6, whence the starting position is again reached and the next jolter or vibrator stroke commences. If one proceeds with compacting the molding sand after the preliminary jolting o'r vibration, then the squeezing piston 9 receives compressed air by way of the line 10 and on its path in the upward direction takes along the table 3 by way of its guide cylinder 4 and presses the mold box filled with sand which is disposed on the table 3 against a pressure plate. The mold box, sand and pressure plate are not illustrated in the drawing for the sake of simplicity. As a result of the movement of the squeezing piston 9 and the table 3 and the operative interconnection between the table 3 and the outlet control element 17 the overlap a of the outlet control in 'FIG. 2 is automatically reduced to the dimension b in FIG. 3 thereby resulting in an automatic earlier discharge of the pressure medium in response to the additional force on the table due to the compacting of the molding sand. The non-adjustable gap 0 in FIG. I and the adjusted distance d of the upper end of the regulating rod 21 from the outlet control element 17 determines the extent for the change of the overlap of the outlet control. The anvil amplitude is reduced by a corresponding amount during vibrating or jolting under squeezing pressure so that the desired reduction of the inertia force occurs. Another adjustment or a readjustment by way of the thread in the part 22 is readily possible at any time. After removal of the cover 25 the securing means 24 can be removed. The desired position can be readily adjusted by rotating the control rod 21 at the projecting end 23 of square configuration.

In this manner a regulating possibility for the jolter or vibrator energy is possible for the relatively inexpensive and simple internal control.

While I have shown and described only one embodiment in accordance with the present invention, it is understood that the same is not limited thereto but is susceptible of numerous changes and modifications as known to those skilled in the art and I therefore do not wish to be limited to the details shown and described herein but intend to cover all such changes modifications as are encompassed by the scope of the appended claims.

What I claim is:

1. A jolter control for a combined jolter and squeezing machine operable with a pressure medium and having a squeezing piston and cylinder, a jolter piston and cylinder and table, comprising: inlet control means the pressure medium; displaceably arranged outlet control means operatively connected to said inlet control means for controlling the discharge of the pressure medium, said outlet control means being displaced by the movement of the squeezing piston; and means for automatically adjusting the discharge of the pressure medium in response to a predetermined force on the table.

2. A jolter control according to claim ll, wherein said automatic adjusting means includes a regulating rod one end of which is operatively connected to said outlet means and the other end of which terminates below said squeezing piston, said outlet control means includes a control edge, said outlet control edge being displaced with respect to the inlet control means by said regulating rod.

3. A jolter control according to claim 2, wherein a spring is provided between said outlet control means and said inlet control means.

4. A jolter control according to claim 3, wherein adjusting means are provided on the end of said regulating rod which terminates below said squeezing piston.

5. A jolter control according to claim 4, wherein the squeezing cylinder is provided with a cover whereby said regulating rod is easily accessible for purposes of adjustment.

6. A jolter control according to claim 1, wherein a spring is provided between said outlet control means and said inlet control means.

7. A jolter control according to claim 3, wherein adjusting means are provided on the end of said regulating rod which terminates below said squeezing piston, said adjusting means adjusts the displacement of said outlet control edge.

8. A jolter control according to claim 7, wherein the squeezing cylinder is provided with a cover whereby said regulating rod is easily accessible for purposes of adjustment.

9. A jolter control according to claim 1, wherein an anvil is disposed in the squeezing cylinder at a predetermined distance from the squeezing piston, a portion of said anvil constituting the jolter piston.

10. A jolter control according to claim 9, wherein said anvil is provided with a shoulder portion at its end opposite the squeezing piston and a spring is provided between one side of said shoulder portion and the squeezing piston.

11. A jolter control according to claim 10, wherein an abutment ring is provided on the other side of said shoulder portion engageable with the jolter cylinder.

12. A jolter control according to claim 11, wherein said inlet control means and said outlet control means are disposed in said portion of said anvil constituting the jolter piston.

13. A jolter control according to claim 12, wherein said inlet control means is provided with an extension upon which said outlet control means is mounted.

14. A jolter control according to claim 13, wherein said extension is disposed in a spring provided between said inlet control means and said outlet control means.

15. A jolter control according to claim 1, wherein said automatic adjusting means includes a regulating rod one end of which is operatively connected to said outlet means and the other end of which terminates below said squeezing piston, and said outlet control means includes a control edge, said outlet control edge being displaced with respect to the inlet control means by said regulating rod. 

1. A jolter control for a combined jolter and squeezing machine operable with a pressure medium and having a squeezing piston and cylinder, a jolter piston and cylinder and table, comprising: inlet control means connected with the table for controlling the supply of the pressure medium; displaceably arranged outlet control means operatively connected to said inlet control means for controlling the discharge of the pressure medium, said outlet control means being displaced by the movement of the squeezing piston; and means for automatically adjusting the discharge of the pressure medium in response to a predetermined force on the table.
 2. A jolter control according to claim 1, wherein said automatic adjusting means includes a regulating rod one end of which is operatively connected to said outlet means and the other end of which terminates below said squeezing piston, said outlet control means includes a control edge, said outlet control edge being displaced with respect to the inlet control means by said regulating rod.
 3. A jolter control according to claim 2, wherein a spring is provided between said outlet control means and said inlet control means.
 4. A jolter control according to claim 3, wherein adjusting means are provided on the end of said regulating rod which terminates below said squeezing piston.
 5. A jolter control according to claim 4, wherein the squeezing cylinder is provided with a cover whereby said regulating rod is easily accessible for purposes of adjustment.
 6. A jolter control according to claim 1, wherein a spring is provided between said outlet control means and said inlet control means.
 7. A jolter control according to claim 3, wherein adjusting means are provided on the end of said regulating rod which terminates below said squeezing piston, said adjusting means adjusts the displacement of said outlet control edge.
 8. A jolter control according to claim 7, wherein the squeezing cylinder is provided with a cover whereby said regulating rod is easily accessible for purposes of adjustment.
 9. A jolter control according to claim 1, wherein an anvil is disposed in the squeezing cylinder at a predetermined distance from the squeezing piston, a portion of said anvil constituting the jolter piston.
 10. A jolter control according to claim 9, wherein said anvil is provided with a shoulder portion at its end opposite the squeezing piston and a spring is provided between one side of said shoulder portion and the squeezing piston.
 11. A jolter control according to claim 10, wherein an abutment ring is provided on the other side of said shoulder portion engageable with the jolter cylinder.
 12. A jolter control according to claim 11, wherein said inlet control means and said outlet control means are disposed in said portion of said anvil constituting the jolter piston.
 13. A jolter control according to claim 12, wherein said inlet control means is provided with an extension upon which said outlet control means is mounted.
 14. A jolter control according to claim 13, wherein said extension is disposed in a spring provided between said inlet control means and said outlet control means.
 15. A jolter control according to claim 1, wherein said automatic adjusting means includes a regulating rod one end of which is operatively connected to said outlet means and the other end of which terminates below said squeezing piston, and said outlet control means includes a control edge, said outlet control edge being displaced with respect to the inlet control means by said regulating rod. 